ABSTRACT
BACKGROUND: Bcl-2 family proteins play a central role in regulating apoptosis. In human, over 20 members of this family have been identified to date. Bfl-1, a member of the Bcl-2 family, has been known to retard apoptosis in various cell lines. However, the function of Bfl-1 remains unclear. METHODS: In order to investigate the Bfl-1 function, we employed yeast two-hybrid system to identify the proteins which are capable of interacting with Bfl-1. The interaction of inhibitor kappaB kinase-beta (IKK-beta) and Bfl-1 was confirmed using glutathione S-transferase pull down assays. To determine which regions of IKK-beta were required for interaction with Bfl-1, we constructed 12 deletion mutants of IKK-beta and 5 deletion mutants of Bfl-1. RESULTS: Bfl-1 interacted with the C-terminal region of IKK-beta which is a subunit of IKK complex, and IKK-beta activity is very important in the NF-kappaB related pathway. In addition, the amino acids 673-745 of IKK-beta were important for Bfl-1 interactions, and amino acids 1-484 of Bfl-1, including Bcl-2 homology domains (BH1, BH2, BH3, BH4), were crucial for IKK-beta interactions. CONCLUSIONS: IKK beta C-terminus contains many serine residues as binding partner of Bfl-1. Our results suggested that Bfl-1 is involved in the NF-kappaB activation through interaction of IKK-beta and Bfl-1. Further studies need to be performed to understand functions of the IKK-beta and Bfl-1 associated with the regulation of the NF-kappaB activation pathway.
Subject(s)
Humans , Amino Acids , Apoptosis , Cell Line , Glutathione Transferase , I-kappa B Kinase , NF-kappa B , Serine , Two-Hybrid System TechniquesABSTRACT
Immunization with dendritic cells (DCs) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL), which is responsible for tumor protection and regression. In this study, we examined whether DCs pulsed with necrotic tumor lysates can efficiently prevent malignant melanoma tumor cell metastasis to the lung. DCs derived from mouse bone marrow were found to produce remarkably elevated levels of IL-12 after being pulsed with the tumor lysates. Moreover, immunization with these DCs induced CTL activation and protected mice from metastasis development by intravenously inoculated tumor cells. In addition, these DCs activated NK cells in vitro in a contact-dependent manner, and induced NK activities in vivo. Furthermore, NK cell depletion before DC vaccination significantly reduced the tumor-specific CTL activity, IFN-g production, and IFN-gamma- inducible gene expression, and eventually interfered with the antitumor effect of tumor-pulsed DCs. Finally, similar findings with respect to NK cell dependency were obtained in the C57BL/ 6J-bg/bg mice, which have severe deficiency in cytolytic activity of NK cells. These data suggest that the antitumor effect elicited by DC vaccination, at least in a B16 melanoma model, requires the participation of both cytolytic NK and CD8+ T cells. The findings of this study would provide important data for the effective design of DC vaccines for cancer immunotherapy.
Subject(s)
Animals , Female , Mice , Antigen Presentation/immunology , CD8-Positive T-Lymphocytes/immunology , Cancer Vaccines/therapeutic use , Cell Line, Tumor , Cytokines/biosynthesis , Dendritic Cells/immunology , Interferon-gamma/biosynthesis , Interleukin-12/biosynthesis , Killer Cells, Natural/immunology , Lung Neoplasms/immunology , Lymphocyte Activation/immunology , Lymphocyte Depletion , Melanoma, Experimental/immunology , Mice, Inbred C57BL , Monocyte Chemoattractant Proteins/biosynthesis , T-Lymphocytes, Cytotoxic/immunologyABSTRACT
BACKGROUND: Immunization of dendritic cells (DCs) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. In this study, we examined whether the uptake of necrotic tumor cells could modulate DC phenotypes and whether the immunization of necrotic tumor cell-loaded DCs could elicit efficient tumor specific immune responses followed by a regression of established tumor burdens. METHODS: We prepared necrotic tumor cell-pulsed DCs for the therapeutic vaccination and investigated their phenotypic characteristics, the immune responses induced by these DCs, and therapeutic vaccine efficacy against colon carcinoma in vivo. Several parameters including phagocytosis of tumor cells, surface antigen expression, chemokine receptor expression, IL-12 production, and NK as well as CTL activation were assessed to characterize the immune response. RESULTS: DCs derived from mouse bone marrow efficiently phagocytosed necrotic tumor cells and after the uptake, they produced remarkably increased levels of IL-12. A decreased CCR1 and increased CCR7 expression on DCs was also observed after the tumor uptake, suggesting that antigen uptake could induce DC maturation. Furthermore, co-culturing of DCs with NK cells in vitro enhanced IL-12 production in DCs and IFN-gamma production in NK cells, which was significantly dependent on IL-12 production and cell-to-cell contact. Immunization of necrotic tumor cell-loaded DCs induced cytotoxic T lymphocytes as well as NK activation, and protected mice against subsequent tumor challenge. In addition, intratumoral or contra-lateral immunization of these DCs not only inhibited the growth of established tumors, but also eradicated tumors in more than 60% of tumor-bearing mice. CONCLUSION: Our data indicate that production of IL-12, chemokine receptor expression and NK as well as CTL activation may serve as major parameters in assessing the effect of tumor cell-pulsed DC vaccine. Therefore, DCs loaded with necrotic tumor cells offer a rational strategy to treat tumors and eventually lead to prolonged survival.
Subject(s)
Animals , Mice , Antigens, Surface , Bone Marrow , Colon , Dendritic Cells , Immunization , Interleukin-12 , Killer Cells, Natural , Phagocytosis , Phenotype , T-Lymphocytes, Cytotoxic , Tumor Burden , VaccinationABSTRACT
BACKGROUND: The S100A2 gene, also known as S100L or CaN19, encodes a protein comprised of 99-amino acids, is a member of the calcium-binding proteins of EF-hand family. According to a recent study, this gene was over-expressed in several early and malignant carcinomas compared to normal tissues. To elucidate the role of S100A2 protein in the process during carcinogenesis, production of monoclonal antibody specific to the protein is essential. METHODS: First, cDNA sequence coding for ORF region of human S100A2 gene was amplified and cloned into an expression vector to produce GST fusion protein. Recombinant S100A2 protein and subsequently, monoclonal antibody to the protein were produced. The specificity of anti-S100A2 monoclonal antibody was confirmed by immunoblot analysis of cross reactivity to other recombinant proteins of S100A family (GST-S100A1, GST-S100A4 and GST-S100A6). To confirm the relation of S100A2 to cervical carcinogenesis, S100A2 protein in early cervical carcinoma tissue was immunostained using the monoclonal antibody. RESULTS: GST-S100A2 recombinant protein was purified by affinity chromatography and then fusion protein was cleaved and S100A2 protein was isolated. The monoclonal antibody (KK0723; Korean patent pending #2001-30294) to the protein was produced and the antibody did not react with other members of EF-hand family proteins such as S100A1, S100A4 and S100A6. CONCLUSION: These data suggest that anti-S100A2 monoclonal antibody produced in this study can be very useful for the early detection of cervical carcinoma and elucidation of mechanism during the early cervical carcinogenesis
Subject(s)
Animals , Humans , Calcium-Binding Proteins , Carcinogenesis , Chromatography, Affinity , Clinical Coding , Clone Cells , DNA, Complementary , Ecthyma, Contagious , Recombinant Proteins , Sensitivity and SpecificityABSTRACT
BACKGROUND: S100A6 is a calcium-binding protein overexpressed in several tumor cell lines including melanoma with high metastatic activity and involved in various cellular processes such as cell division and differentiation. To detect S100A6 protein in patient' samples (ex, blood or tissue), it is essential to produce a monoclonal antibody specific to the protein. METHODS: First, cDNA coding for ORF region of human S100A6 gene was amplified and cloned into the expression vector for GST fusion protein. We have produced recombinant S100A6 protein and subsequently, monoclonal antibodies to the protein. The specificity of anti-S100A6 monoclonal antibody was confirmed using recombinant S100A recombinant proteins of other S100A family (GST-S100A1, GST-S100A2 and GST-S100A4) and the cell lysates of several human cell lines. Also, to identify the specific recognition site of the monoclonal antibody, we have performed the immunoblot analysis with serially deleted S100A6 recombinant proteins. RESULTS: GST-S100A6 recombinant protein was induced and purified. And then S100A6 protein excluding GST protein was obtained and monoclonal antibody to the protein was produced. Monoclonal antibody (K02C12-1; patent number, 330311) has no cross-reaction to several other S100 family proteins. It appears that anti- S100A6 monoclonal antibody reacts with the region containing the amino acid sequence from 46 to 61 of S100A6 protein. CONCLUSION: These data suggest that anti-S100A6 monoclonal antibody produced can be very useful in development of diagnostic system for S100A6 protein.
Subject(s)
Animals , Humans , Amino Acid Sequence , Antibodies, Monoclonal , Cell Division , Cell Line , Cell Line, Tumor , Clinical Coding , Clone Cells , DNA, Complementary , Ecthyma, Contagious , Melanoma , Recombinant Proteins , Sensitivity and SpecificityABSTRACT
BACKGROUND: S100A6 is a calcium-binding protein overexpressed in several tumor cell lines including melanoma with high metastatic activity and involved in various cellular processes such as cell division and differentiation. To detect S100A6 protein in patient' samples (ex, blood or tissue), it is essential to produce a monoclonal antibody specific to the protein. METHODS: First, cDNA coding for ORF region of human S100A6 gene was amplified and cloned into the expression vector for GST fusion protein. We have produced recombinant S100A6 protein and subsequently, monoclonal antibodies to the protein. The specificity of anti-S100A6 monoclonal antibody was confirmed using recombinant S100A recombinant proteins of other S100A family (GST-S100A1, GST-S100A2 and GST-S100A4) and the cell lysates of several human cell lines. Also, to identify the specific recognition site of the monoclonal antibody, we have performed the immunoblot analysis with serially deleted S100A6 recombinant proteins. RESULTS: GST-S100A6 recombinant protein was induced and purified. And then S100A6 protein excluding GST protein was obtained and monoclonal antibody to the protein was produced. Monoclonal antibody (K02C12-1; patent number, 330311) has no cross-reaction to several other S100 family proteins. It appears that anti- S100A6 monoclonal antibody reacts with the region containing the amino acid sequence from 46 to 61 of S100A6 protein. CONCLUSION: These data suggest that anti-S100A6 monoclonal antibody produced can be very useful in development of diagnostic system for S100A6 protein.
Subject(s)
Animals , Humans , Amino Acid Sequence , Antibodies, Monoclonal , Cell Division , Cell Line , Cell Line, Tumor , Clinical Coding , Clone Cells , DNA, Complementary , Ecthyma, Contagious , Melanoma , Recombinant Proteins , Sensitivity and SpecificityABSTRACT
Mycobacterium tuberculosis is capable of growing and survival within macrophage. The purpose of this study was to identify the genes regulated by infection of mycobacteria in human monocytic THP-1 cells. We used the differential display reverse transcriptase polymerase chain reaction (DD RT-PCR) and nothern blot analysis to confirm the differentially expressed genes from THP-1 cells infected with live Mycobacterium tuberculosis H37Rv, heat-kille Mycobacterium tuberculosis H37Rv and live Mycobacterium bovis BCG. Among many up or down-regulated clones, 27 clones were sequenced and compared with known genes on GenBank. Thirteen of over-expressed clones from THP-1 cells infected with live Mycobacterium tuberculosis H37Rv were identical to human prothymosin alpha, eight were novel clones and six clones showed homology with Human ferritin H chain, Escherichia coli bgl, Mouse RNA-dependent EIF-2 alpha kinase, E. coli htrL, Hyaluronan receptor and T cell receptor. Our result suggests that Mycobacterium tuberculosis might regulate prothymosin alpha gene transcription in monocytic THP-1 cell.
Subject(s)
Animals , Humans , Mice , Hyaluronan Receptors , Clone Cells , Databases, Nucleic Acid , Escherichia coli , Eukaryotic Initiation Factor-2 , Ferritins , Macrophages , Mycobacterium bovis , Mycobacterium tuberculosis , Mycobacterium , Phosphotransferases , Receptors, Antigen, T-Cell , Reverse Transcriptase Polymerase Chain Reaction , Up-RegulationABSTRACT
D variant of encephalomyocarditis (EMC-D) virus causes diabetes in susceptible mice by direct infection and cytolysis of pancreatic beta cells. cDNA covering the major outer capsid protein (VP1) of EMC-D virus was cloned into Mycobacterium bovis bacillus Calmette-Guerin (BCG). None of the SJL/J male mice, immunized with live recombinant BCG-VP1, became diabetic when challenged with highly diabetogenic EMC-D virus. But the control mice inoculated with normal BCG or rBCG transformed with vector alone developed diabetes in the same challenge. VP1-specific antibodies including neutralizing antibodies were markedly increased as time went on and reached to the maximum titer at week 10 after a single immunization. The plateau of the titer lasted longer than following 4 weeks. Guinea pigs immunized with the live rBCG-VP1 showed strong delayed type hypersensitivity (DTH) to the VP1of EMC-D virus. It means that the live rBCG-VP1 elicit efficient humoral and cell-mediated imrnune responses against EMC-D virus, resulting in prevention of virus-induced diabetes in susceptible mice.